Figure 3-14 defines the OPEN parameter list. Table 3-10 describes the functions of the fields within the 0 PEN parameter list.
3 .. 36 Token-Ring Network Adapter
BYTE 0 2 4 6 8 10 12 14 16 18 20 22 24
26 27 28 30
Open Options Node Address (high)
Node Address Node Address (low) Group Address (high)
Group Address (low) Functional Address (high)
Functional Address (low) Receive List Size Transmit List Size
Buffer Size Exp. RAM Start Address
Exp. RAM End Address X MIT Buffer Min Count XMIT Buffer Max Count Product ID Address (high) Product ID Address (low) Figure 3-14. OPEN Parameter List
Table 3-10. OPEN Parameter Functions
BYTE 0,1 OPEN OPTIONS. The bit functions of the Open Options field are provided below:
WRAP INTERFACE. Setting bit 0 to one on OPEN negates the Ring Insertion Process and causes all user transmit data to appear as user receive data. The data is transmitted on the lobe from the attached product to the wiring concentrator. This option can be used for system interface debug, system interface DMA testing, or lobe media testing. A CLOSE command must be issued to terminate WRAP mode.
DISABLE HARD ERROR. If bit 1 is set to a one, the RING ST ATUS Hard Error and TRANSMIT BEACON Interrupts will not be generated.
DISABLE SOFT ERROR. If bit 2 is set to a one, the RING ST A TUS Soft Error Interrupt will not be generated.
PASS ADAPTER MAC FRAMES. Bit 3 is used to specify to the Adapter what action is to be taken when Adapter class MAC frames are received, but are not supported by the Adapter. If this bit is set to one the MAC frames will be passed to the attached system as normal receive data. If this bit is set to zero, the Adapter will ignore all unsupported Adapter MAC frames, purge them from internal Adapter buffers, and transmit a negative response MAC frame to the originating station.
PASS ATTENTION MAC FRAMES. If bit 4 is set to one, all Attention MAC frames that are not equal to the last Attention MAC frame received will be passed to the system as normal receive data following normal processing by the Adapter.
PAD ROUTING FIELD. If bit 5 is set to one, the Adapter will pad the Routing Field to 18 bytes. If no RI field is present in the received frame, the entire field will be padded to 18 bytes. This option is voided if the current buffer's data count is not at least 32 bytes. In this case the frame will be transferred as if the bit was set to zero.
FRAME HOLD. If bit 6 is set to one, the Adapter will wait for an entire frame to be read from the ring before initiating the DMA transfer of the frame to the system. If this bit is a zero, then a DMA transfer will be initiated whenever an Adapter internal buffer is filled.
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Table 3-10. OPEN Parameter Functions (Continued) in the Claim-Token Process if another Adapter detects the need for contention and initiates the Claim-Token Process. This bit has no effect if this Adapter detects the need for contention and initiates the Claim-Token Process.
PASS BEACON MAC FRAMES. If this bit is set to one, the Adapter will pass Beacon MAC frames. After passing the Beacon MAC frame, the next Beacon MAC frame will be passed only if the source address or the Beacon Type Subvector
changes.
RESERVED. Bits 9-15 are ignored.
NODE ADDRESS. This 6-byte field specifies the node address for the Adapter. If this address is all zeros, the Adapter will use the Adapter Address read from the address module. If the Node Address is not zero then the following check is made. Byte Obits 0,1 must be set to "01". If any of the above checks fail, the Adapter will report a Node Address Error.
GROUP ADDRESS. This 32-bit field specifies the Group Address and will cause the Adapter to receive messages that are sent to the Group Address.
The GROUP ADDRESS can be any value. Bit 0 is ignored by the Adapter.
Group Address recognition is disabled by specifying the GROUP ADDRESS as zero.
BYTES 12-15 FUNCTIONAL ADDRESS. This 32-bit field specifies the Functional Address and will cause the Adapter to receive messages that are sent to the
Functional Address. FUNCTIONAL ADDRESS bits 0, 30, and 31 are ignored by the Adapter. A zero value disables the Functional Address feature.
BYTES 16-17 RECEIVE LIST SIZE. This 16-bit field indicates the number of bytes the Adapter will read when obtaining a Receive List from the attached system. A decimal value of 0, 14, 20, or 26 is required. If zero, the default value of 26 is used.
BYTES 18-19 TRANSMIT LIST SIZE. This 16-bit field indicates the number of bytes the Adapter will read when obtaining a Transmit List from the attached system.
A decimal value of 0, 14, 20, or 26 is required. If zero, the default value of 26 is used.
BYTES 20-21 BUFFER SIZE. This 16-bit field indicates the Adapter's internal buffer size in bytes. BUFFER SIZE must be greater than or equal to 96. The three low-order bits must be zero. If this field is zero, a default value of 112 bytes is used.
Table 3-10. OPEN Parameter Functions (Continued)
BYTES 22-23 EXPANSION RAM START ADDRESS. This 16-bit parameter defines an expansion RAM start address within the Adapter. This additional RAM may be used for transmit and/ or receive buffers. If this field is zero, no external RAM is defined within the Adapter. If bit 15 is set to one, the existing internal Adapter RAM will not be used for transmit or receive buffers, defaulting to the expansion RAM. The expansion RAM within the Adapter begins at X'4006'and ends at X'7FFF'. The expansion RAM and decode logic are tested, but if bad parity is detected, an ADAPTER CHECK Parity Error will be issued.
BYTES 24-25 EXPANSION RAM END ADDRESS. This 16-bit field specifies the ending address of Adapter expansion RAM. The Expansion RAM End Address for the Adapter is X'7FFE'. If the EXPANSION RAM START ADDRESS is zero, this field is ignored.
BYTE 26 TRANSMIT BUFFER MINIMUM COUNT. This byte parameter contains the number of Adapter buffers that are to be reserved as transmit buffers. These buffers will be reserved for transmit only and will never be used for receive.
If zero is specified, no buffers are reserved for transmit. The minimum transmit buffer count must be equal to or less than the transmit maximum buffer count (byte 27).
BYTE 27 TRANSMIT BUFFER MAXIMUM COUNT. This byte parameter contains the maximum number of Adapter buffers that are to be used for transmit. A
minimum of two buffers must be available for receive. If this parameter is set to zero, a default value of six buffers is used. The product of TRANSMIT
BUFFER MAXIMUM COUNT and (BUFFER SIZE -8) determines the maximum size frame that the Adapter can transmit.
BYTES 28-31 PRODUCT ID ADDRESS. This 32-bit field contains a 24-bit address of the attached system Product ID. Eighteen bytes are transferred to the Adapter during OPEN. If a Request Station Attachment MAC frame is received from the Network Manager, the bytes are read from the specified location in
adapter memory. See the IBM Token-Ring Network Architecture Reference manual for more detail concerning the Product ID.
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